摘要
基于2018年浙江省嘉兴市14个环境国控站点的O3历史资料与气象要素,研究O3与气象要素的关系,并结合差分吸收臭氧雷达的垂直臭氧探测资料,分析近地层O3廓线变化特征.结果表明,嘉兴地区发生高浓度O3污染的关键气象要素为24~36℃的大气温度和36%~77%的相对湿度,24℃以上的大气温度与77%以下的相对湿度可作为启动预警O3污染的气象指标.差分吸收臭氧雷达监测结果显示,无论O3超标天与清洁天,在垂直方向上其浓度随高度先升后降,在600~800m范围出现峰值;O3污染时段,在中午到午后低空形成持续向下的O3输送带,这种低空O3与地表O3的叠加机制加重地表O3污染程度,导致地表O3超标与低空高浓度相伴出现;其廓线日变化规律表现出800m以下浓度在夜间和凌晨梯度不显著,日出后近地层O3随时间快速增加,中午和午后持续高值,傍晚随时间逐渐下降的特征.后向轨迹分析表明,10,500,1000m高度层的气流后向轨迹聚类有相似性,500m处沿闽浙海岸线的轨迹簇对应O3较10m处来自海上的轨迹簇高,这与500m处前体物输送堆积和紫外线辐射增强有关.污染过程近地层气流来向紧贴地面,但中高层有明显下沉气流使得O3前体物在500m附近堆积,是造成2个典型污染过程中垂直方向上O3高值出现在500m左右的原因之一.
Based on O3 surface data in 2018 from 14 monitor stations and meteorological factors of Jiaxing city,Zhejiang Province,this study analyzed the relationship between O3 and meteorological factors.The vertical profile of O3 was characterized by a differential absorption O3 lidar.Temperature and relative humidity were the dominating factors for high concentration O3 pollution,with the range of 24~36℃ and 36%~77%,respectively.The temperature above 24℃ and the relative humidity below 77% can be used as the meteorological threshold for early warning of O3 pollution.The O3 lidar results showed that the vertical O3profiles were similar between episodic and clean days,which exhibited an O3 peak between 600~800m,while the O3 concentrations decreased beyond this range.During the O3 episodic period,O3 was transported downward to the ground^level from noon to afternoon.This superposition of near-surface ozone and ground-level ozone aggravates ground-level O3 pollution,leading to an exceedance of air quality standard for O3 at both near-surface and ground-level.The O3 below 800m was relatively constant at night and in the early morning.Ground-level O3 increased rapidly after sunrise until reaching a peak in the afternoon.O3 decreased gradually in the later afternoon.The backward trajectories clustering analysis showed that there was a similarity in the clusters of air masses at 10m,500m,and 1000m.Air masses that traveled along the coastline of Fujian and Zhejiang provinces at 500m exhibited higher O3 than the air masses from the ocean at 10m.That was related to the transport accumulation of the precursors and the stronger ultraviolet radiation at 500m.During the episodic events,the near-surface air masses exhibited an unchanged height.The downdraft in the middle and upper boundary layer led to the accumulation of O3 precursor near 500m.That was one of the reasons for the high O3 near 500m observed in two typical pollution episodes.
作者
何国文
吴兑
吴晟
李梅
邓涛
吴伟超
李莉
程鹏
袁婧
张颖龙
宋烺
孙嘉胤
陶丽萍
梁粤
谭健
周振
HE Guo-wen;WU Dui;WU Cheng;LI Mei;DENG Tao;WU Wei-chao;LI Li;CHENG Peng;YUAN Qian;ZHANG Ying-long;SONG Lang;SUN Jia-yin;TAO Li-ping;LIANG Yue;TAN Jian;ZHOU Zhen(Guangdong Engineering Research Centre for Online Atmospheric Pollution Source Appointment Mass Spectrometry System,Institute of Mass Spectrometry and Atmospheric Environment,Jinan University,Guangzhou 510632,China;Institute of Tropical and Marine Meteorology,China Meteorological Administration,Guangzhou 510640;Jiaxing Environmental Monitoring Station,Jiaxing 314000,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2020年第10期4265-4274,共10页
China Environmental Science
基金
国家自然科学基金资助项目(41475004,41605002)
2019年广东省重点领域研发计划(2019B110206001)
广州市珠江科技新星项目(201710010006)
嘉兴市臭氧源解析服务项目(40118117)。
关键词
差分吸收臭氧雷达
O3污染
气象要素
垂直分布
嘉兴
differential absorption lidar
ozone pollution
meteorological factor
vertical distribution
Jiaxing